/*
* pqPutMsgEnd: finish constructing a message and possibly send it
*
* Returns 0 on success, EOF on error
*
* We don't actually send anything here unless we've accumulated at least
* 8K worth of data (the typical size of a pipe buffer on Unix systems).
* This avoids sending small partial packets. The caller must use pqFlush
* when it's important to flush all the data out to the server.
*/
int
pqPutMsgEnd(PGconn *conn)
{
pqPutMsgEndNoAutoFlush(conn);
if (conn->outCount >= 8192)
{
int toSend = conn->outCount - (conn->outCount % 8192);
if (pqSendSome(conn, toSend) < 0)
return EOF;
/* in nonblock mode, don't complain if unable to send it all */
}
return 0;
}
/*
*
*
* Control Message has msg_type='C'.
* Control Message is consumed by Receiver thread on mirror side.
*
* Data Message has msg_type='M'.
* Data Message is inserted in Shared memory and consumed by Consumer
* thread on mirror side.
*/
bool
FileRepConnClient_SendMessage(
FileRepConsumerProcIndex_e messageType,
bool messageSynchronous,
char *message,
uint32 messageLength)
{
char msgType = 0;
int status = STATUS_OK;
#ifdef USE_ASSERT_CHECKING
int prevOutCount = filerep_conn->outCount;
#endif /* // USE_ASSERT_CHECKING */
switch (messageType)
{
case FileRepMessageTypeXLog:
msgType = '1';
break;
case FileRepMessageTypeAO01:
msgType = '2';
break;
case FileRepMessageTypeWriter:
msgType = '3';
break;
case FileRepMessageTypeShutdown:
msgType = 'S';
break;
default:
return false;
}
/**
* Note that pqPutMsgStart and pqPutnchar both may grow the connection's internal buffer, and do not
* flush data
*/
if (pqPutMsgStart(msgType, true, filerep_conn) < 0)
{
return false;
}
if (pqPutnchar(message, messageLength, filerep_conn) < 0)
{
return false;
}
/*
* Server side needs complete messages for mode-transitions so disable
* auto-flush since it flushes partial messages
*/
pqPutMsgEndNoAutoFlush(filerep_conn);
/* assert that a flush did not occur */
Assert(prevOutCount + messageLength + 5 == filerep_conn->outCount); /* the +5 is the amount
* added by
* pgPutMsgStart */
/*
* note also that we could do a flush beforehand to avoid having
* pqPutMsgStart and pqPutnchar growing the buffer
*/
if (messageSynchronous || filerep_conn->outCount >= file_rep_min_data_before_flush)
{
int result = 0;
/* wait and timeout will be handled by pqWaitTimeout */
while ((status = pqFlushNonBlocking(filerep_conn)) > 0)
{
/* retry on timeout */
while (!(result = pqWaitTimeout(FALSE, TRUE, filerep_conn, time(NULL) + file_rep_socket_timeout)))
{
if (FileRepSubProcess_IsStateTransitionRequested())
{
elog(WARNING, "segment state transition requested while waiting to write data to socket");
status = -1;
break;
}
}
if (result < 0)
{
ereport(WARNING,
(errcode_for_socket_access(),
errmsg("could not write data to socket, failure detected : %m")));
status = -1;
break;
}
if (status == -1)
{
break;
}
}
if (status < 0)
{
return false;
}
Assert(status == 0);
return true;
}
return true;
}
